Changes between Initial Version and Version 1 of TracFastCgi


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Timestamp:
Mar 18, 2016, 5:22:35 PM (6 years ago)
Author:
trac
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  • TracFastCgi

    v1 v1  
     1= Trac with FastCGI
     2
     3[[TracGuideToc]]
     4[[PageOutline(2-5, Contents, floated)]]
     5
     6[http://www.fastcgi.com/ FastCGI] interface allows Trac to remain resident much like with [wiki:TracModPython mod_python] or [wiki:TracModWSGI mod_wsgi]. It is faster than external CGI interfaces which must start a new process for each request.  Additionally, it is supported by much wider variety of web servers.
     7
     8Note that unlike mod_python, FastCGI supports [http://httpd.apache.org/docs/suexec.html Apache SuEXEC], ie run with different permissions than the web server runs with. `mod_wsgi` supports the `WSGIDaemonProcess` with user / group parameters to achieve the same effect.
     9
     10'''Note for Windows:''' Trac's FastCGI does not run under Windows, as Windows does not implement `Socket.fromfd`, which is used by `_fcgi.py`. If you want to connect to IIS, you may want to try [trac:TracOnWindowsIisAjp AJP]/[trac:TracOnWindowsIisAjp ISAPI].
     11
     12== Simple Apache configuration
     13
     14There are two FastCGI modules commonly available for Apache: `mod_fastcgi` and
     15`mod_fcgid` (preferred). The latter is more up-to-date.
     16
     17The following sections focus on the FCGI specific setup, see also [wiki:TracModWSGI#ConfiguringAuthentication] for configuring the authentication in Apache.
     18
     19Regardless of which cgi module is used, be sure the web server has executable permissions on the cgi-bin folder. While FastCGI will throw specific permissions errors, mod_fcgid will throw an ambiguous error if this has not been done. Connection reset by peer: mod_fcgid: error reading data from FastCGI server.
     20
     21=== Set up with `mod_fastcgi`
     22
     23`mod_fastcgi` uses `FastCgiIpcDir` and `FastCgiConfig` directives that should be added to an appropriate Apache configuration file:
     24{{{
     25# Enable fastcgi for .fcgi files
     26# (If you're using a distro package for mod_fcgi, something like
     27# this is probably already present)
     28<IfModule mod_fastcgi.c>
     29   AddHandler fastcgi-script .fcgi
     30   FastCgiIpcDir /var/lib/apache2/fastcgi
     31</IfModule>
     32LoadModule fastcgi_module /usr/lib/apache2/modules/mod_fastcgi.so
     33}}}
     34Setting `FastCgiIpcDir` is optional if the default is suitable. Note that the `LoadModule` line must be after the `IfModule` group.
     35
     36Configure `ScriptAlias` or similar options as described in TracCgi, but
     37calling `trac.fcgi` instead of `trac.cgi`.
     38
     39Add the following to the Apache configuration file (below the `FastCgiIpcDir` line) if you intend to set up the `TRAC_ENV` as an overall default:
     40{{{
     41FastCgiConfig -initial-env TRAC_ENV=/path/to/env/trac
     42}}}
     43
     44Alternatively, you can serve multiple Trac projects in a directory by adding this:
     45{{{
     46FastCgiConfig -initial-env TRAC_ENV_PARENT_DIR=/parent/dir/of/projects
     47}}}
     48
     49=== Set up with `mod_fcgid`
     50
     51Configure `ScriptAlias` (see TracCgi for details), but call `trac.fcgi` instead of `trac.cgi`:
     52{{{
     53ScriptAlias /trac /path/to/www/trac/cgi-bin/trac.fcgi/
     54}}}
     55Note the slash at the end.
     56
     57To set up Trac environment for `mod_fcgid` it is necessary to use `DefaultInitEnv` directive. It cannot be used in `Directory` or `Location` context, so if you need to support multiple projects, try alternative environment setup below.
     58
     59{{{
     60DefaultInitEnv TRAC_ENV /path/to/env/trac/
     61}}}
     62
     63=== alternative environment setup
     64
     65A better method to specify path to the Trac environment is to embed the path into `trac.fcgi` script itself. That doesn't require configuration of the server environment variables, works for both [trac:FastCgi] modules as well as for [http://www.lighttpd.net/ lighttpd] and CGI:
     66{{{
     67import os
     68os.environ['TRAC_ENV'] = "/path/to/projectenv"
     69}}}
     70or:
     71{{{
     72import os
     73os.environ['TRAC_ENV_PARENT_DIR'] = "/path/to/project/parent/dir"
     74}}}
     75
     76With this method different projects can be supported by using different `.fcgi` scripts with different `ScriptAliases`.
     77
     78See [https://coderanger.net/~coderanger/httpd/fcgi_example.conf this fcgid example config] which uses a !ScriptAlias directive with trac.fcgi with a trailing / like this:
     79{{{
     80ScriptAlias / /srv/tracsite/cgi-bin/trac.fcgi/
     81}}}
     82
     83== Simple Cherokee Configuration
     84
     85The configuration on Cherokee's side is quite simple. You will only need to know that you can spawn Trac as an SCGI process.
     86You can either start it manually, or better yet, automatically by letting Cherokee spawn the server whenever it is down.
     87First set up an information source in cherokee-admin with a local interpreter:
     88
     89{{{
     90Host:
     91localhost:4433
     92
     93Interpreter:
     94/usr/bin/tracd —single-env —daemonize —protocol=scgi —hostname=localhost —port=4433 /path/to/project/
     95}}}
     96
     97If the port was not reachable, the interpreter command would be launched. Note that, in the definition of the information source, you will have to manually launch the spawner if you use a ''Remote host'' as ''Information source'' instead of a ''Local interpreter''.
     98
     99After doing this, we will just have to create a new rule managed by the SCGI handler to access Trac. It can be created in a new virtual server, trac.example.net for instance, and will only need two rules. The '''default''' one will use the SCGI handler associated to the previously created information source.
     100The second rule will be there to serve the few static files needed to correctly display the Trac interface. Create it as ''Directory rule'' for ''/common'' and just set it to the ''Static files'' handler and with a ''Document root'' that points to the appropriate files: ''$TRAC_LOCAL/htdocs/'' (where $TRAC_LOCAL is a directory defined by the user or the system administrator to place local trac resources).
     101
     102Note:\\
     103If the tracd process fails to start up, and cherokee displays a 503 error page, you might be missing the [http://trac.saddi.com/flup python-flup] package.\\
     104Python-flup is a dependency which provides trac with SCGI capability. You can install it on debian based systems with:
     105{{{
     106sudo apt-get install python-flup
     107}}}
     108
     109== Simple Lighttpd Configuration
     110
     111The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.lighttpd.net/ Lighttpd].
     112
     113Lighttpd is a secure, fast, compliant and very flexible web-server that has been optimized for high-performance environments. It has a very low memory footprint compared to other web servers and takes care of CPU load.
     114
     115For using `trac.fcgi`(prior to 0.11) / fcgi_frontend.py (0.11) with Lighttpd add the following to your lighttpd.conf:
     116{{{
     117#var.fcgi_binary="/usr/bin/python /path/to/fcgi_frontend.py" # 0.11 if installed with easy_setup, it is inside the egg directory
     118var.fcgi_binary="/path/to/cgi-bin/trac.fcgi" # 0.10 name of prior fcgi executable
     119fastcgi.server = ("/trac" =>
     120   
     121                   ("trac" =>
     122                     ("socket" => "/tmp/trac-fastcgi.sock",
     123                      "bin-path" => fcgi_binary,
     124                      "check-local" => "disable",
     125                      "bin-environment" =>
     126                        ("TRAC_ENV" => "/path/to/projenv")
     127                     )
     128                   )
     129                 )
     130}}}
     131
     132Note that you will need to add a new entry to `fastcgi.server` for each separate Trac instance that you wish to run. Alternatively, you may use the `TRAC_ENV_PARENT_DIR` variable instead of `TRAC_ENV` as described above, and you may set one of the two in `trac.fcgi` instead of in `lighttpd.conf` using `bin-environment`, as in the section above on Apache configuration.
     133
     134Note that Lighttpd has a bug related to 'SCRIPT_NAME' and 'PATH_INFO' when the uri of fastcgi.server is '/' instead of '/trac' in this example (see [trac:#2418]). This is fixed in Lighttpd 1.5, and under Lighttpd 1.4.23 or later the workaround is to add `"fix-root-scriptname" => "enable"` as a parameter of fastcgi.server.
     135
     136For using two projects with lighttpd add the following to your `lighttpd.conf`:
     137{{{
     138fastcgi.server = ("/first" =>
     139                   ("first" =>
     140                    ("socket" => "/tmp/trac-fastcgi-first.sock",
     141                     "bin-path" => fcgi_binary,
     142                     "check-local" => "disable",
     143                     "bin-environment" =>
     144                       ("TRAC_ENV" => "/path/to/projenv-first")
     145                    )
     146                  ),
     147                  "/second" =>
     148                    ("second" =>
     149                    ("socket" => "/tmp/trac-fastcgi-second.sock",
     150                     "bin-path" => fcgi_binary,
     151                     "check-local" => "disable",
     152                     "bin-environment" =>
     153                       ("TRAC_ENV" => "/path/to/projenv-second")
     154                    )
     155                  )
     156                )
     157}}}
     158
     159Note that field values are different. If you prefer setting the environment variables in the `.fcgi` scripts, then copy/rename `trac.fcgi`, eg to `first.fcgi` and `second.fcgi`, and reference them in the above settings.
     160Note that the above will result in different processes in any event, even if both are running from the same `trac.fcgi` script.
     161
     162{{{
     163#!div class=important
     164'''Note''' It's very important the order on which server.modules are loaded, if mod_auth is not loaded '''BEFORE''' mod_fastcgi, then the server will fail to authenticate the user.
     165}}}
     166
     167For authentication you should enable mod_auth in lighttpd.conf 'server.modules', select auth.backend and auth rules:
     168{{{
     169server.modules              = (
     170...
     171  "mod_auth",
     172...
     173)
     174
     175auth.backend               = "htpasswd"
     176
     177# Separated password files for each project
     178# See "Conditional Configuration" in
     179# http://trac.lighttpd.net/trac/file/branches/lighttpd-merge-1.4.x/doc/configuration.txt
     180
     181$HTTP["url"] =~ "^/first/" {
     182  auth.backend.htpasswd.userfile = "/path/to/projenv-first/htpasswd.htaccess"
     183}
     184$HTTP["url"] =~ "^/second/" {
     185  auth.backend.htpasswd.userfile = "/path/to/projenv-second/htpasswd.htaccess"
     186}
     187
     188# Enable auth on trac URLs, see
     189# http://trac.lighttpd.net/trac/file/branches/lighttpd-merge-1.4.x/doc/authentication.txt
     190
     191auth.require = ("/first/login" =>
     192                ("method"  => "basic",
     193                 "realm"   => "First project",
     194                 "require" => "valid-user"
     195                ),
     196                "/second/login" =>
     197                ("method"  => "basic",
     198                 "realm"   => "Second project",
     199                 "require" => "valid-user"
     200                )
     201               )
     202
     203}}}
     204Note that Lighttpd (v1.4.3) stops if the password file doesn't exist.
     205
     206Note that Lighttpd doesn't support 'valid-user' in versions prior to 1.3.16.
     207
     208Conditional configuration is also useful for mapping static resources, ie serving out images and CSS directly instead of through FastCGI:
     209{{{
     210# Aliasing functionality is needed
     211server.modules += ("mod_alias")
     212
     213# Set up an alias for the static resources
     214alias.url = ("/trac/chrome/common" => "/usr/share/trac/htdocs")
     215
     216# Use negative lookahead, matching all requests that ask for any resource under /trac, EXCEPT in
     217# /trac/chrome/common, and use FastCGI for those
     218$HTTP["url"] =~ "^/trac(?!/chrome/common)" {
     219# Even if you have other fastcgi.server declarations for applications other than Trac, do NOT use += here
     220fastcgi.server = ("/trac" =>
     221                   ("trac" =>
     222                     ("socket" => "/tmp/trac-fastcgi.sock",
     223                      "bin-path" => fcgi_binary,
     224                      "check-local" => "disable",
     225                      "bin-environment" =>
     226                        ("TRAC_ENV" => "/path/to/projenv")
     227                     )
     228                   )
     229                 )
     230}
     231}}}
     232
     233The technique can be easily adapted for use with multiple projects by creating aliases for each of them, and wrapping the fastcgi.server declarations inside conditional configuration blocks.
     234Also there is another way to handle multiple projects and it's to use TRAC_ENV_PARENT_DIR instead of TRAC_ENV and use global auth, let's see an example:
     235{{{
     236#  This is for handling multiple projects
     237  alias.url       = ( "/trac/" => "/path/to/trac/htdocs/" )
     238
     239  fastcgi.server += ("/projects"  =>
     240                      ("trac" =>
     241                        (
     242                          "socket" => "/tmp/trac.sock",
     243                          "bin-path" => fcgi_binary,
     244                          "check-local" => "disable",
     245                          "bin-environment" =>
     246                            ("TRAC_ENV_PARENT_DIR" => "/path/to/parent/dir/of/projects/" )
     247                        )
     248                      )
     249                    )
     250#And here starts the global auth configuration
     251  auth.backend = "htpasswd"
     252  auth.backend.htpasswd.userfile = "/path/to/unique/htpassword/file/trac.htpasswd"
     253  $HTTP["url"] =~ "^/projects/.*/login$" {
     254    auth.require = ("/" =>
     255                     (
     256                       "method"  => "basic",
     257                       "realm"   => "trac",
     258                       "require" => "valid-user"
     259                     )
     260                   )
     261  }
     262}}}
     263
     264Changing date/time format also supported by lighttpd over environment variable LC_TIME:
     265{{{
     266fastcgi.server = ("/trac" =>
     267                   ("trac" =>
     268                     ("socket" => "/tmp/trac-fastcgi.sock",
     269                      "bin-path" => fcgi_binary,
     270                      "check-local" => "disable",
     271                      "bin-environment" =>
     272                        ("TRAC_ENV" => "/path/to/projenv",
     273                        "LC_TIME" => "ru_RU")
     274                     )
     275                   )
     276                 )
     277}}}
     278For details about languages specification see [trac:TracFaq TracFaq] question 2.13.
     279
     280Other important information like the [wiki:TracInstall#MappingStaticResources mapping static resources advices] are useful for non-fastcgi specific installation aspects.
     281]
     282
     283Relaunch Lighttpd and browse to `http://yourhost.example.org/trac` to access Trac.
     284
     285Note about running Lighttpd with reduced permissions: If nothing else helps and trac.fcgi doesn't start with Lighttpd settings `server.username = "www-data"`, `server.groupname = "www-data"`, then in the `bin-environment` section set `PYTHON_EGG_CACHE` to the home directory of `www-data` or some other directory accessible to this account for writing.
     286
     287== Simple !LiteSpeed Configuration
     288
     289The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.litespeedtech.com/ LiteSpeed].
     290
     291!LiteSpeed web server is an event-driven asynchronous Apache replacement designed from the ground-up to be secure, scalable, and operate with minimal resources. !LiteSpeed can operate directly from an Apache config file and is targeted for business-critical environments.
     292
     293 1. Please make sure you have a working install of a Trac project. Test install with "tracd" first.
     294
     295 2. Create a Virtual Host for this setup. From now on we will refer to this vhost as !TracVhost. For this tutorial we will be assuming that your Trac project will be accessible via:
     296{{{
     297http://yourdomain.com/trac/
     298}}}
     299
     300 3. Go "!TracVhost → External Apps" tab and create a new "External Application".
     301{{{
     302Name: MyTracFCGI       
     303Address: uds://tmp/lshttpd/mytracfcgi.sock
     304Max Connections: 10
     305Environment: TRAC_ENV=/fullpathto/mytracproject/ <--- path to root folder of trac project
     306Initial Request Timeout (secs): 30
     307Retry Timeout (secs): 0
     308Persistent Connection   Yes
     309Connection Keepalive Timeout: 30
     310Response Bufferring: No
     311Auto Start: Yes
     312Command: /usr/share/trac/cgi-bin/trac.fcgi  <--- path to trac.fcgi
     313Back Log: 50
     314Instances: 10
     315}}}
     316
     317 4. Optional: If you need to use htpasswd based authentication. Go to "!TracVhost → Security" tab and create a new security Realm.
     318
     319{{{
     320DB Type: Password File
     321Realm Name: MyTracUserDB               <--- any name you wish and referenced later
     322User DB Location: /fullpathto/htpasswd <--- path to your htpasswd file
     323}}}
     324
     325If you don’t have a htpasswd file or don’t know how to create the entries within one, go to http://sherylcanter.com/encrypt.php, to generate the user:password combos.
     326
     327 5. Go to "!PythonVhost → Contexts" and create a new FCGI Context.
     328
     329{{{
     330URI: /trac/                              <--- URI path to bind to python fcgi app we created   
     331Fast CGI App: [VHost Level] MyTractFCGI  <--- select the trac fcgi extapp we just created
     332Realm: TracUserDB                        <--- only if (4) is set. select realm created in (4)
     333}}}
     334
     335 6. Modify `/fullpathto/mytracproject/conf/trac.ini`
     336
     337{{{
     338#find/set base_rul, url, and link variables
     339base_url = http://yourdomain.com/trac/ <--- base url to generate correct links to
     340url = http://yourdomain.com/trac/      <--- link of project
     341link = http://yourdomain.com/trac/     <--- link of graphic logo
     342}}}
     343
     344 7. Restart !LiteSpeed, “lswsctrl restart”, and access your new Trac project at:
     345
     346{{{
     347http://yourdomain.com/trac/
     348}}}
     349
     350== Simple Nginx Configuration
     351
     352Nginx is able to communicate with FastCGI processes, but can not spawn them. So you need to start FastCGI server for Trac separately.
     353
     354 1. Nginx configuration with basic authentication handled by Nginx - confirmed to work on 0.6.32
     355 {{{
     356    server {
     357        listen       10.9.8.7:443;
     358        server_name  trac.example;
     359
     360        ssl                  on;
     361        ssl_certificate      /etc/ssl/trac.example.crt;
     362        ssl_certificate_key  /etc/ssl/trac.example.key;
     363
     364        ssl_session_timeout  5m;
     365
     366        ssl_protocols  SSLv2 SSLv3 TLSv1;
     367        ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
     368        ssl_prefer_server_ciphers   on;
     369
     370        # it makes sense to serve static resources through Nginx (or ``~ [/some/prefix]/chrome/(.*)``)
     371        location ~ /chrome/(.*) {
     372             alias /home/trac/instance/static/htdocs/$1;
     373        }
     374
     375        # You can copy this whole location to ``location [/some/prefix](/login)``
     376        # and remove the auth entries below if you want Trac to enforce
     377        # authorization where appropriate instead of needing to authenticate
     378        # for accessing the whole site.
     379        # (Or ``~ location /some/prefix(/.*)``.)
     380        location ~ (/.*) {
     381            auth_basic            "trac realm";
     382            auth_basic_user_file /home/trac/htpasswd;
     383
     384            # socket address
     385            fastcgi_pass   unix:/home/trac/run/instance.sock;
     386
     387            # python - wsgi specific
     388            fastcgi_param HTTPS on;
     389
     390            ## WSGI REQUIRED VARIABLES
     391            # WSGI application name - trac instance prefix.
     392            # (Or ``fastcgi_param  SCRIPT_NAME  /some/prefix``.)
     393            fastcgi_param  SCRIPT_NAME        "";
     394            fastcgi_param  PATH_INFO          $1;
     395
     396            ## WSGI NEEDED VARIABLES - trac warns about them
     397            fastcgi_param  REQUEST_METHOD     $request_method;
     398            fastcgi_param  SERVER_NAME        $server_name;
     399            fastcgi_param  SERVER_PORT        $server_port;
     400            fastcgi_param  SERVER_PROTOCOL    $server_protocol;
     401            fastcgi_param  QUERY_STRING       $query_string;
     402
     403            # For Nginx authentication to work - do not forget to comment these
     404            # lines if not using Nginx for authentication
     405            fastcgi_param  AUTH_USER          $remote_user;
     406            fastcgi_param  REMOTE_USER        $remote_user;
     407
     408            # for ip to work
     409            fastcgi_param REMOTE_ADDR         $remote_addr;
     410
     411            # For attchments to work
     412            fastcgi_param    CONTENT_TYPE     $content_type;
     413            fastcgi_param    CONTENT_LENGTH   $content_length;
     414        }
     415    }
     416}}}
     417 1. Modified trac.fcgi:
     418 {{{
     419#!/usr/bin/env python
     420import os
     421sockaddr = '/home/trac/run/instance.sock'
     422os.environ['TRAC_ENV'] = '/home/trac/instance'
     423
     424try:
     425     from trac.web.main import dispatch_request
     426     import trac.web._fcgi
     427
     428     fcgiserv = trac.web._fcgi.WSGIServer(dispatch_request,
     429          bindAddress = sockaddr, umask = 7)
     430     fcgiserv.run()
     431
     432except SystemExit:
     433    raise
     434except Exception, e:
     435    print 'Content-Type: text/plain\r\n\r\n',
     436    print 'Oops...'
     437    print
     438    print 'Trac detected an internal error:'
     439    print
     440    print e
     441    print
     442    import traceback
     443    import StringIO
     444    tb = StringIO.StringIO()
     445    traceback.print_exc(file=tb)
     446    print tb.getvalue()
     447
     448}}}
     449 1. reload nginx and launch trac.fcgi like that:
     450 {{{#!sh
     451trac@trac.example ~ $ ./trac-standalone-fcgi.py
     452}}}
     453
     454The above assumes that:
     455 * There is a user named 'trac' for running trac instances and keeping trac environments in its home directory
     456 * `/home/trac/instance` contains a trac environment
     457 * `/home/trac/htpasswd` contains authentication information
     458 * `/home/trac/run` is owned by the same group the nginx runs under
     459  * and if your system is Linux the `/home/trac/run` has setgid bit set (`chmod g+s run`)
     460  * and patch from ticket #T7239 is applied, or you'll have to fix the socket file permissions every time
     461
     462Unfortunately nginx does not support variable expansion in fastcgi_pass directive.
     463Thus it is not possible to serve multiple Trac instances from one server block.
     464
     465If you worry enough about security, run Trac instances under separate users.
     466
     467Another way to run Trac as a FCGI external application is offered in ticket #T6224
     468
     469----
     470See also:  TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracCgi CGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]